Performance analysis of sorption thermal battery for high-density cold energy storage enabled by novel tube-free evaporator

Cold energy storage is of significance to thermal management of electrical devices, air-conditioning, building energy-saving, and renewable energy utilization. Sorption thermal battery (STB) has distinct advantage of high-energy-density cold storage based on liquid-gas vaporization heat when compared with conventional cold storage technologies in the form of sensible heat or solid-liquid latent heat. However, STB suffers from low -power-density energy storage due to its poor heat and mass transfer during reversible solid-gas sorption pro-cesses. Here, a novel tube-free evaporator is proposed and designed for STB to reduce thermal resistance and accelerate sorption rate. The effects of the tube-free evaporator on the heat and mass transfer of STB prototype for cold energy storage are investigated and discussed. The thermal resistance of evaporator can be reduced by 94.9% and the sorption-evaporation rate can be accelerated by 24.2% by using the novel tube-free evaporator. Correspondingly, the STB prototype exhibits superior cold storage performance with improved energy density and peak power density by 32.8% and 50%, respectively. The heat design strategy of tube-free evaporator provides a new solution to develop high-energy/power-density STB for cold storage.

Automated summary

Cold energy storage is important for thermal management and energy utilization. Sorption thermal battery (STB) has advantages over conventional technologies, but suffers from low-power-density energy storage. This study proposes a novel tube-free evaporator to reduce thermal resistance and accelerate sorption rate in STB, leading to improved cold storage performance.